Chemical product and process for making the same



- as color, solubility and Patented Mar. 19, 1946 CWMICAL PRODUCT AND PROCESS FOR MAKING m SAW William E. Hanford, was, re

amnion-REE.

du Pont de Nemonrsa Company. Wilmington, Del., a corporation of Delaware No Drawing, Application awn 2 3, 1943, Serial No. 484,213

27 Claims.

This invention relates to the preparation of polyaromatic nitro compounds by the nitration of aromatic telomers.

It is known that nitro groups may be introduced into organic molecules containing benzenoid nuclei by the action of nitrating agents such as fuming nitric acid or a mixture of nitric and sulfuric acids. It is also known that these nitro compounds may be reduced to the corresponding amino compounds which may then be linked with other molecules by the diazotization and coupling reactions to give dyestuffs or pigments, The properties of the derivatives, such stability to light, depend to a great extent upon the chemical constitution of the nitrated organic compounds which are used in their preparation.

It is an object of this invention to prepare new nitro and amino compounds. Another object is to provide'new polynitro and polyamino compounds having at least one other substituent. A further object is to prepare nitro and amino substituted telomers. Other objects will appear hereinafter. I

These objects have been accomplished by, nitrating the aromatic nuclei of a telomer, each taxomon unit of which contains an aromatic nucleus, and reducing the resulting nitro compounds to amino compounds.

Telomers are new types of compounds produced by a process called telomerization. In copending U. S. application Serial No. 438,466, filed April 10, 1942, it has been pointed out that the novelty of this reaction is such that, for adequate description, it has been found necessary to coin new terms to describe the reaction and the participants therein. The reaction has been called "telomerization (from Greek telos, meaning end plus Greek mer meaning "part). Telomerization is definedas the process of reacting, under polymerization conditions, a molecule YZ which is called a telogen" with more than one unit of a polymerizable compound having ethylenic uhsaturation called a taxogen to form products called telomers having the formula Y(A) 112, wherein (AM is a divalent radical formed by the chemical union, with the formation of new carbon bonds, of the taxogen, the unit A being called a taxomon," n being any integer greater than one, and Y and Z being fragments of the telogen attached to the terminal taxomons.

Telomers of aromatic taxogens are new com. positions of matter described in pending U. S. application Serial No. 464,519, filed November 4, 1942. They are prepared by the reaction of arcmetic taxogens, i. e., polymerizable olefinic compounds containing aromatic substituents (such as styrene, vinyl benzoate, etc.) with telogens, i. e., telomerizing agents (such as carbon tetrachloride, ethyl trichloroacetate, hydrochloric acid, etc.). The preparation of such telomers is fully described in U. 8. application Serial No. 464,519, filed November 4, 1942, which is made a part of this disclosure by reference.

A monomeric taxogen, such as styrene, is heated with 1 to 3 molecular equivalents of the telogen and approximately 0.01 molecular equivslant of a telomerization catalyst, such as benzoyl peroxide, at 100-150" C. for a period of about 8 hours. The product is separated from the excess of telogen and from an remaining monomeric styrene by a suitable process, such as, for example, distillation or steam distillation. The reaction temperature and the concentrations of the reactants are chosen to give a product having the desired molecular weight, according to the general rule that the average {molecular weight of the product is decreased by using a higher temperature or by increasing the concentration of the telogen. When one mole of styrene is heated with two moles of carbon tetrachloride and 0.004 mole of benzoyl peroxide at 86 C. for hours, the product, Cl-(CzHz.CeHs) 11.CC13, is found to have an average chain length, n, of 21 styrene units. When 1.3 moles of carbon tetrachloride are used and the temperature is maintained at 120 C. for 8 hours, the product is found to have a chain length, n, of 15. When styrene is heated with 2 moles of bromoform and 0.0066 mole of benzoyl peroxide at 90 to C. for 24 hours, the product, after separation from excess bromoform by distillation under diminished pressure, is found to have an average chain length of 8 styrene units. Ethyl trichloroacetate gives a product of even lowermolecular weight.

A telomer of an aromatic taxogen is treated with a nitreting agent to produce a polynitro compound. The product contains a multiplicity of nitro groups and at least one other substituent, the latter being derived from a fragment of the telogen used in the preparation of the telomer. By "nitrating agent" is meant any reagent capable of introducing 9. nitro group into a benzenoid nucleus. It has been found that the telomers may be nitrated by the same reagents known to be effective for monomeric aromatic organic compounds, for example, fuming nitric acid.

The nitrated telomers are reduced to the corresponding amino compounds by the usual agents for the reduction of nitro groups, such as, for

example, powdered iron-and aqueous acetic acid, tin and hydrochloric acid, or catalytic hydrogenation. The nitrated styrene -telomers are much easier to reduce than are nitrated polymers such as polystyrene. Thus, a nitrated styrene/ carbon tetrachloride telomer such as the above can be suspended in a solvent such as glacial acetic acid and reduced by the action of hydrogen in the presence of a palladium-on-charcoal catalyst.

In order that the invention may be more fully understood, the following examples are given by way'of illustration. Parts are by weight.

Example I A. styrene-carbon tetrachloride telomer containing 6.75% chlorine (average molecular weight 2100, average composition C1(C2Ii'i-CQH5)1B.'l-CC13) is ground to a fine powder. Twenty parts of the telomer is then added in small portions to 150 parts of fuming nitric acid (specific gravity 1.49) while the mixture is stirred and cooled to maintain a temperature of to C. The telomer dissolves readily in the acid to give a clear, dark solution. As soon as all of the telomer is dissolved, the solution is poured into a large volume of pure ice-water. The yellow precipitate is washed with water until free of acid, filtered ofi,

" and dried in vacuum. The yield is quantitative,

and the product contains approximately one nitro group per benzenoid nucleus, as shown by the nitrogen content.

Nitrogen Chlorine Found n Page?! Percent 0.1mm cans..aaissns een:: 8.91 21% By fractional crystallization of the styrene telomer itself individual telomers may be obtained which can be nitrated as above to give the corresponding nitro compounds. These can be reduced as in Examples II and III to the corresponding amino compounds.

Example II A nitrated styrene-carbon tetrachloride telomer having an average composition corresponding to Cl(C2H3.C6H4NO2)18.'l-CC13 is ground with 3.3 parts I Example III Nine parts of a nitrated styrene-carbon tetrachloride telomer, obtained as in Example I, is dissolved in 50 parts of glacial acetic acid and 5 parts of an aqueous suspension of palladium-on-charcoal catalyst (containing 0.025 part of palladium) is added. After hydrogenation by heating at 150 to 200 C. until hydrogen is no longer absorbed, the mixture is cooled, centrifuged and filtered. Ammonium hydroxide is then added to thesolu- 'tion and the precipitate is filtered and purified by crystallization from a water-acetone solution,

each of which contains an aromatic hydrocarbon nucleus. It is also preferred that the telomer have a halogen in an end group.

The taxogens can be aromatic compounds, having side chain olefinic unsaturatlon, such as styrene, alpha-methyl styrene, beta-ethyl styrene, l-vinyl-4-chlorobenzene, 1,4-divinylbenzone, vinyl naphthalenes, indene, etc. The preferred taxogens are polymerizable aromatic mono-oleflnic hydrocarbons. Especially preferred are aromatic vinyl compounds of from 8 to 12 carbon atoms. such as styrene, nuclear substituted styrenes, and vinyl naphthalene.

Hydrogen chloride and saturated estadrides or inorganic acids are suitable telogens. Halogenated derivatives of aliphatic hydrocarbons, such as C014, CHCla, CHaCh, CHgClI, CHSOCIII, CHaBr, and especially halogenated methanes having at least 2 halogen atoms, are preferred estadrides.

The telomer may be nitrated with fuming 'nitric acid in the presence or absence of a solvent. The use of an inert solvent such as nitrobenzene is especially advantageous if it is desired to introduce less than 1 nitro group per aromatic nucleus. The telomer dissolves and undergoes reaction with the evolution of heat, and it is generally desirable to regulate the speed of the reactionat the outset by adding the telomer to the nitration mixture insmall portions with eflicient stirring and, if necessary, cooling. Products containing approximately 1 nitro group per aromatlc nucleus are preferred for most purposes, and these are in general obtained by dissolving the telomer in 3 to 10 parts of turning nitric acid at room temperature or below, and then allowing the mixture to stand at room temperature for several hours. The mixture is then poured into cold water, whereupon the nitro compound separates as a precipitate. It is filtered and washed with water until free of acid.

The extent of nitration can be varied at will by controlling the temperature and concentration of the nitrating agent. Nitrated telomers can then be made which contain from 2 nitro groups per telomer to 2 nitro groups per aromatic nucleus.

The nitro-substituted telomers can be reduced to the corresponding amino compounds by means known in the art, and Examples 11'. and III illustrate this step. The amino telomers are capable of forming salts with acids, and these salts are soluble in water. Treatment of the aqueous solution of the hydrochloride of a polyamino telomer with a diazotizing agent, such as sodium nitrate, gives rise to the corresponding diazonium salt. This shows all the reactions of an aromatic diazonium compound. They can be used as reagents for insolubilizing dyes or dye intermediates, or they can be coupled with the usual azo coupling components to produce colored compounds of high molecular weight.

The process of the invention produces new compounds, usually as mixtures of compounds diii'erlng in the length 01' the taxomon chain and the number of nitro or amino groups. The preaaoenao ferred compounds can be represented by the formula Y-(An Hr)':,-Z-Wz YZ which has been made to react with the ole-.

fin, W is a member of the group consisting of No: and NH2, and the w groups are substituted for hydrogen (represented by the minus H in the formula) in aromatic nuclei.

Molecular distillation, fractional crystallization or fractional precipitation of the telomer mixture may be employed to isolate( individual telomer's for nitration. Fractional crystallization is the preferred method in separating individual nitro or amino telomers from mixtures thereof.

The products are useful as intermediates for the production of dispersing agents, surfaceactive agents, dyestuffs and pigments.

It is apparent thatmany widely different embodiments of this invention may be made without departing from the spirit and scope thereof, and, therefore, it is not intended to be limited except as indicated in the appended claims.

I claim: I

1. A mixture of linear polymeric materials having'nitro groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring -CH-CHI H0 units and, terminally, one Cl and one -CCla radical.

2. A mixture of linear polymeric materials having nitro groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring CHCH:-

0115 units and, terminally, two monovalent radicals which together make up a polychlorinated methane.

3. A mixture of linear polymeric materials having nitro groups substituted for hydrogen on aromatic carbon of linear polymeric materials hav- ,ing a chain of two to thirty recurring CHOHr- HI units and, terminally, two monovalent radicals which together make up a polyhalogenated methane.

4. A mixture of linear polymeric materials having amino groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring -CH-CH:

0H5 units and, terminally, one --Cl and one -CCh radical.

5. A mixture of linear polymeric materials having amino groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring -CHCH:-

H: units and, terminally, two monovalent radicals which together make up a polychlorinated methane.

6. A mixture of linear polymeric materials having amino groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring -oncms 7 units and, terminally, two monovalent radicals which together make up a polyhalogenated methone.

'7. A mixture of linear polymeric materials having nitrogen groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring -CHCHrunits and, terminally. one --C1 and one -CCla radical, said nitrogen groups being selected from the class consisting of the nitro group and the amino group.

8. A mixture of linear polymeric materials having nitrogen groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units and, terminally, two monovalent radicals v which together make up a polychlorinated methane, said nitrogen groups being selected from the class consisting of the nitro group and the amino group.

9. A mixture oi linear polymeric materials having nitrogen groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units and, terminally, two monovalent radicals which together make up a polyhalogenated methane, said nitrogen groups being selected from the class consisting of the nitro group and the amino V units, wherein R is an aromatic radical of from six to ten carbon atoms, and, terminally, one -C1 and one CCl3 radical.

11. A mixture of linear polymeric materials having nitro groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units, wherein R is an aromatic radical of from aromatic carbon of linear polymeric materials having a chain of two to thirty recurring -o H-CHrunits, wherein R. is an aromatic radical of from six to ten carbon atoms, and, terminally, two monovalent radicals which together make up a polyhalogenated methane.

13. A mixture of linear polymeric materials having amino groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units, wherein R. is an aromatic radical of from six to ten carbon atoms, and, terminally, one -Cl and one CCla radical.

having nitro groups substituted for hydrogen on aromatic carbon 01' linear polymeric materials having a chain of two to thirty recurring units, wherein R is an aromatic hydrocarbon radical of from six to ten carbon atoms, and, terminally, one Cl and one-0C1: radical.

20. A mixture of linear polymeric materials having nitro groups substituted for hydrogen on aromatic carbon of linear polymeric materials 14. A mixture of linear polymeric materials having amino groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring Ara-on units, wherein Ris an aromatic radical of irom six to ten carbon atoms, and, terminally, two

monovalent radicals which together make up a polychlorinated methane.

15. A mixture of linear polymeric materials having amino groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units, wherein R. is an aromatic radical of from six to ten carbon atoms, and, terminally, two monovalent radicals which together make up a polyhalogenated methane.

16. A mixture of linear polymeric materials having nitrogen groups substituted for hydrogen a on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units, wherein R is an aromatic radical of from six to ten carbon atoms, and, terminally, one C1 and one --CCls radical, said nitrogen groups being selected from the class consisting of the nitro group and the amino group.

17. A mixture of linear polymeric materials having nitrogen groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units, wherein R is an aromatic radical of from six to ten carbon atoms, and, terminally, two monovalent radicals which together make up a polyhalogenated methane, said nitrogen groups being selected from the class consisting of the nitro group and the amino group.

19. A mixture of linear polymeric materials 75 having a chain of two to thirty recurrin -on'--om units, wherein R is an aromatic hydrocarbon radical of from six to ten carbon atoms, and, terminally, two monovalent radicals which together make up a polychlorinated methane.

21. A mixture or linear polymeric matefials having nitro groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units, whereinR is an aromatic hydrocarbon radical 01 from six to ten carbonatoms. and, terminally, two. monovalent radicals which together make up a polyhalogenated methane.

22. A mixture of linear polymeric materials having amino groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring units; wherein R is an aromatic hydrocarbon radical of from six to ten carbon atoms, and, terminally, one Cl and one CCla' radical.

23. A mixture 01' linear polymeric materials having amino groups substituted for hydrogen on aromatic. carbon of linear polymeric materials having a chain oftwo to thirty recurring units, wherein It, is an aromatic hydrocarbon radical of mm six to ten carbon atoms, and,

terminally, two monovalent radicals which together make up a polychlorinated methane.

24. A mixture of linear polymeric materials having amino groups substituted for hydrogen 5 on aromatic carbon of linear polymeric materials having a chain or two to thirty recurring -on-cn.

units, wherein R is an aromatic hypdrocarbon radical 01' from six to ten carbon atoms, and, terminally, two monovalent radicals which together make up a polyhalogenated methane.-

25. A mixtur of linear polymeric materials having nitrogen groups substituted for hydrogen on aromatic carbon of linear polymeric materials having a chain of two to thirty recurring -CH-CHr- 7 units, wherein R is an aromatic hydrocarbon radical oi from six to ten carbon atoms, and, terminally, one -C1 and one CCla radical, said nitrogen groups being selected from the class consisting of the nitro group and the amino group.

asoegree 26. A mixture of linear polymeric materials having nitrogen groups substituted hydrogen having nitrogen groups substituted for hydrogen on aromatic carbon of linear polymer or aromatic carbon of linear polymeric materials having a chain of two thirty recurs J having a chain of two to thirty" recurring OE--035- -('}H-CH: g R t units, wherein R is an aromatic hydrocarbon units, wherein R is an aromatic hydrocarbon radical of from six to ten carbon. atoms, radical of from six to ten carbon atoms, and, terminally, two monovaient radios which to terminally, two monovaient radicals which toto gether make up a polyhalogenated 1n hens, said gether make up a polychlorinated methane, said nitrogen groups being selected from 0 ct. nitrogen groups being selected from the class consisting of the nitro group and the gro p. sisting of the nitro'group and the amino group. 2'1. A: mixture of linear polymeric materials Certificate of Correction Patent No. 2,396,786. March 1%, i946. WILLIAM E. HANFORD It IS hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Page 4, second column, line 59, claim 24, for hypdrocarbon read hydrocarbon; page 5, first column, line 3, claim 26, for .or aromatic read on aromatic; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflioe.

Signed and sealed this 13th day of August, A. D. 1946.

LESLIE FRAZER, First Assistant Uommz'ssz'oner of Patents. 

